Screw-cutting plate.



No. 820,334. PATENTED MAY s, 1906. P. BAGKSTRGM. SCREW CUTTING PLATE. APPLIUATION FILED SEPT. 18,1905.

fgiifimmmlnventor Witnesses Attorneys PETTER BiiOKSTROM, F MINNEAPOLIS, MINNESOTA.

SCREW-CUTTING PLATE.

Specification of Letters Patent.

ratented May 8, 1906.

Application filed September 18, 1905. Serial No. 278,920.

- plates for the purpose of threading or rethreading bolts and rods of various dimensions; and among the objects of the invention are to simplify and improve the construction and operation of this class of devices and to provide an implement which may be conveniently adjusted and securely tightened upon any desired point of an old bolt for the purpose of rethreading the same.

With these and other ends in view, which will readily appear as the nature of the invention is better understood, the same consists in the improved construction and novel arrangement and combination of parts,which will be hereinafter fully described, and particularly pointed out in the claim.

In the accompanying drawings has been illustrated a simple and preferred form of the invention, it being, however, understood that no limitation is necessarily made to the precise structural details therein exhibited, but that changes, alterations, and modifications within the scope of the invention may be made when desired.

In said drawings, Figure 1 is aperspective view showing the improved screwcutting plate in the act of being applied to a bolt for the purpose of rethreading the same. Fig. 2 is a plan view, partly in section, showing the plate in position for operation upon a bolt. Fig. 3 is a sectional detail view taken on the plane indicated by the line 3 3 in Fig. 2. Fig. 4 is a sectional detail view taken on the plane indicated by the line 4 4 in Fig. 2. Fig. 5 is a perspective view of the auxiliary clampingrace detached.

Corresponding parts in the several figures are indicated throughout by similar characters of reference.

The improved screw-cutting plate is composed of two members 1 and 2, each having a handle 3, and one of said members 1 belng provided with laterally-extending lugs 4 adjacent to the handle portion thereof, between which the extremity of the member 2 is pivotally mounted, as upon a pin 5, the handles 3 3 of the members 1' and 2 extending in 0p 0- site directions, as clearly seen in Figs. 1 and 2 Thread-cutting dies 6 6 of difierent dimen sions are formed in the adjacent edges of the plate members 1 and 2', and the latter is provided, adjacent to the handle thereof, with a pivoted clip 7, carrying a set-screw 8, the point of which is adapted to en age a shallow recess 9 near the extremity of the plate member 1, which ma thus be engaged by said screw and forced 1n the direction of the member 2. The device may thus be clamped and tightened upon a rod or bolt for the purpose of threading or rethreading the same.

It will be seen that the improved device, constructed as herein described, will be especially serviceable for various kinds of'repair work, since the plate may be adjusted upon a bolt at a distance from the point thereof, when the thread of said bolt may be recut by turning the plate in an outward direction upon the bolt,.as indicated in 1 of the drawings. This procedure may be frequently resorted to when the bolts that are to be rethreaded may not be readily removedfrom the arts with which they are connected.

T e plate member 1 has been shown as provided in its outer ed e with a longitudinal groove 10, adapted for t e reception of a claw 11, formed at one end of a clamp 12, the opposite end of which is provided with a flange 13, which is hook-shaped, as shown, so as to be capable of engaging over the outer edge of the plate member 2, said hook-shaped flange being rovided with a set-screw 14, ada ted to be tlghtened against the outer edge 0' the clamp member. When large bolts or rods are to be operated upon, it is obviously important that t e screw-cutting plate be securely tightened thereon in order that threads of the proper depth may be out. By adjusting the lmproved clamping device upon the plate, adjacent to the side of the bolt or rod that is being operated upon, which is distant from the cli 7, the plate members may be very secure y tightened without incurring severe strain upon the pivotal connecting means of the plate members, which would be injurious by causing the thread-cutting dies to be eventually thrown out of alinement with each other. I

From the. foregoing description, taken in connection with the drawings hereto annexed, the operation and advantages of this invention will be readily understood by those skilled in the art to which it appertains. The constructionof the improved device is extremely simple, and it will be found to be IIO efficient and serviceable for the purposes set clamp having a oove-en aging claw and a forth. plate-engaging ange an a plate-engaging Having thus described the invention, what set-screw insaid flan Z5. 7 is claimed is In testimony. that claim the foregoing as I5 5 In a device of the-class described, a plate my own I have hereto aflixed my signatureln inelnbfir having a llongitudinal gliOOVG and the presence of two witnesses.

atera -exten 1n u s, amatin ate Inember pivbted betwe en aid lugs a n d having a 1 PER BAQKSTROM ivoted screw-carrying clip, said plate mem- Witnesses: 1o ers being provided with oppositelyextend J. D. GREEN,

ing handles; in combination with an auxiliary ERNST GAUFFIN. 

